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(chemical engineering)
Enclosing of materials in capsules from well below 1 micrometer to over 2000 micrometers in diameter.



the enclosure of small solid particles and their aggregates (granules) or drops of liquid within a thin, durable shell with various definite properties, such as permeability, fusibility, and solubility (or insolubility) in given media. The size of microcapsules is usually 10-1 to 10-4 cm. The material of the shell makes up a few percent of the total mass of the capsule.

Microencapsulation consists in dispersion of the material in a suitable gaseous or liquid medium, with subsequent coating of the particles or droplets of the dispersed phase by a layer of the capsule material, which is introduced into the system as a separate phase or separates from the surrounding (dispersion) medium as a result of physical or chemical processes. The microcapsule shells may at first be liquid, solidifying upon heating or cooling or the action of chemical reagents. Various macromolecular compounds, including those of biological origin, such as gelatin, are often used as the capsule material.

The technological methods of microencapsulation are extremely varied. They are based on physical and chemical processes of condensation, phase transitions, and various types of surface interphase effects. In each specific case, the methods used are dictated by the properties and composition of the components, as well as by the intended use of the microcapsules.

Microencapsulation is used to protect various powdered products from caking and the action of moisture and atmospheric oxygen, to avoid premature interaction of chemically reactive compounds, and to provide safe storage and handling of aggressive and poisonous substances. Microencapsulation is finding increased application in the production of timed-release drugs, biologically active substances for agriculture (pesticides, growth regulators, and fertilizers), and various composition materials, such as glues.


Encyclopedia of Polymer Science and Technology, vol. 8. New York,
1968. Page 719.


References in periodicals archive ?
Various materials are used as encapsulating agents, especially the milk protein, which present gelifying and emulsifying properties becoming interesting in the microencapsulation of probiotics (Doherty et al.
Alves, Microencapsulation with chitosan by spray drying for industry Applications--A review.
Microencapsulation is imparting new properties to innumerable products spread across various fields.
The technique of microencapsulation may be defined as the technology for coating particles or droplets of liquid or gaseous material, forming capsules in miniature, which may release their contents at controlled rates and/or under specific conditions (FAVARO-TRINDADE et al.
FlowCAM[R] particle imaging and analysis system automatically detects, images and measures individual particles and agglomerates during the microencapsulation process in real time.
Microencapsulation is a process by which certain bioactive substances are retained within a matrix or wall system in order to protect them from deleterious environmental conditions, prevent loss and gradually release them under controlled conditions (Anal and Stevens, 2005; Anal et al.
In order to overcome those problems and to enable peanut sprouts to be utilized in functional foods, microencapsulation can be a possible solution.
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According to the arrangement, PCT will perform microencapsulation for parsing beta pancreatic islets for xenotransplantation using piglet pancreata.
The company offers a wide range of natural and highly concentrated marine omega-3 oils that are rich in PUFAs (EPA and DHA), vegetable omega-6 oils and high potency technology for the microencapsulation of active ingredients.
The Applicant has endeavoured to modernize drug manufacturing and introduce latest pharmaceutical technologies in Pakistan and have therefore brought state of the art microencapsulation technology from Germany at the investment cost of around Rs.
Specific topics include architecture of thin solid films by the GLAD technique, transparent polymer nanocomposites as a new class of functional materials, nanostructures by ion irradiation, microencapsulation, decorative PVD coatings, microwave chemistry and nanomaterials, aluminum-based nanostructured coatings deposited by magnetron sputtering for corrosion protection of steels, nanolayered hard coatings for mechanical applications, plating of nanocomposite coatings, nanostructured coatings, characterization of coatings, and high temperature oxidation resistance of nanocomposite coatings.